PSYC 2301 Lecture Notes - Lecture 4: Mean Squared Error, Squared Deviations From The Mean, Standard Deviation
Document Summary
Tools you will need: summation notation (chapter 1, central tendency (chapter 3) 4. 1 overview: variability can be defined several ways. A quantitative distance measure based on the differences between scores. Describes distance of the spread of scores or distance of a score from the mean: purposes of measure of variability. Measure how well an individual score represents the distribution. Three measures of variability: the range, the variance, the standard deviation. 4. 2 the range: the distance covered by the scores in a distribution. From smallest value to highest value: for continuous data, real limits are used range = url for xmax lrl for xmin, based on two scores, not all the data. 4. 3 standard deviation and variance for a population: most common and most important measure of variability is the standard deviation. A measure of the standard, or average, distance from the mean.
